1. Field of the Invention:
This invention relates to a system for determining the trajectory of a moving object, and more particularly to a trajectory-analyzer system and method thereof.
2. Description of the Prior Art:
There are many known devices and systems that have been employed and are presently being employed to determine the, trajectory of various high-speed objects. However, these known devices are limited in their uses, and they have features that restrict their applications to particular situations or circumstances, none of which are related to those having problems solved by the present invention.
Many pitcher-training devices have been devised but all known devices suffer from two serious drawbacks. First, they are physical objects that prevent the play of the game; and second, they only compute where the ball passes through one plane of a three-dimensional strike zone.
There are other devices, normally applied to the game of golf, that by using remote sensors could be used to track a ball; but all such known devices require that the object to be tracked be specially treated or in some other way visually be made unique. Since there is nothing visually unique about a baseball, neither the adaptation of a golf-training device nor a pitcher-training device would permit the normal play of a baseball game without any form of alteration or pre-treatment of the baseball. That the invention permits the game to be played without obstruction or tampering with the players, or any objects, makes it unique and is crucial to the success of the invention.
A further unique feature of the invention that greatly enhances its utility and clarity of presentation is the computation of a nominal trajectory (the trajectory the ball would take if the pitcher had only nominal spin on the ball). This nominal trajectory permits quantitative determination of the amount of curvature, or displacement, that the pitcher is able to impart to the ball through various types of pitches (curve ball, knuckle ball, sinker, slider, etc.).
As an example of the prior art one may refer to Linn, Jr. in U.S. Pat. No. 4,163,941, which uses television cameras in a device for measuring the velocity of the head of a golf club. This device uses the time/position relationships to establish the position of a single uniquely colored object (the head of the golf club) and to send pulses when that object is detected. Thus, Linn's system will only work in a situation in which the object to be tracked happens to have a unique color or must be pre-treated to acquire a unique color. Since in the baseball application, the objective of the present invention is to compute the trajectory of a pitched baseball without causing any interference to the game or altering any of the objects associated with it, the objectives of this invention and that of Linn are quite different. Moreover, other than using the well-known relationships that convert time to position using a video sensor, the mechanization of the systems is entirely different, and must in fact be so for the system to work.
Still another example of the prior art is disclosed in Satio et al, U.S. Pat. No. 4,005,261, which uses a scene cancellation technique through controlling voltages in a pickup tube. This device records all moving objects within the field of view, but without the ability to discriminate between these moving objects as is required, and performed, in the present invention. The computerized scene-cancellation process of the present invention is totally different in concept and design, and must be so to incorporate the logic for object identification, trajectory definition, and computer-graphics display.